In all of Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) system, Code Division Multiple Access (CDMA) 2000, multi-carrier-frequency aggregation technology within the same Radio Access Technology (RAT) is introduced. The multi-carrier-frequency aggregation technology means that multi-carrier-frequency resources may be used to transmit the same user's data, here referred to as intra-system multi-carrier aggregation technology, to improve the user's peak rate. At present, multi-carrier aggregation technology within a single RAT has been mature. With the increase in the number of carrier aggregation, the service peak rate of a User Equipment (UE) will come to another bottle neck. Considering that networks of multiple modes (i.e. multiple RATs) will simultaneously coexist for a long time in present wireless communication networks, e.g. all of UMTS, Global System for Mobile communication (GSM), CDMA 2000 and LTE networks will coexist for a long time, a multimode terminal has been applied very widely. In order to further improve the peak rate, it is possible to make the UE operate in networks of two modes simultaneously. For example, the UE operates in UTMS and LTE systems simultaneously, or the UE operates in LTE and GSM EDGE Radio Access Network (GERAN) systems simultaneously, as well as between other systems, etc.
When the UE operates in networks of two modes or more modes simultaneously, a node that aggregates/divides data of the two or more networks is referred to as a data aggregation/division node. The data aggregation/division node may be used as a carrier aggregation control node or an anchor point which is used for performing carrier data division/aggregation control. A link corresponding to an anchor point is a primary RAT link, and a link corresponding to a non-anchor point is an auxiliary RAT link. For example, when the UE operates in UTMS and LTE systems simultaneously, link control nodes of UTMS and LTE systems are a Radio Network Controller (RNC) and an evolved NodeB (eNB) respectively. If the RNC of the UMTS system is an anchor point, the primary RAT link is a UMTS link and the auxiliary RAT link is an LTE link. Conversely, if the eNB of the LTE system is an anchor point, the primary RAT link is an LTE link and the auxiliary RAT link is a UMTS link.
In the prior art, when the UE is switched under aggregation of multiple RAT carriers, if only a source node and a target node are involved according to the switching scheme of a single RAT link, the continuity of the throughput of data transmission may not be ensured.